CA2049171A1 - Surface coating material for tundish and steel ladle - Google Patents
Surface coating material for tundish and steel ladleInfo
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- CA2049171A1 CA2049171A1 CA002049171A CA2049171A CA2049171A1 CA 2049171 A1 CA2049171 A1 CA 2049171A1 CA 002049171 A CA002049171 A CA 002049171A CA 2049171 A CA2049171 A CA 2049171A CA 2049171 A1 CA2049171 A1 CA 2049171A1
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- dolomite
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/6303—Inorganic additives
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- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/08—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by adding porous substances
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/03—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite
- C04B35/06—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on magnesium oxide, calcium oxide or oxide mixtures derived from dolomite based on oxide mixtures derived from dolomite
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/632—Organic additives
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/66—Monolithic refractories or refractory mortars, including those whether or not containing clay
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00034—Physico-chemical characteristics of the mixtures
- C04B2111/00146—Sprayable or pumpable mixtures
- C04B2111/00155—Sprayable, i.e. concrete-like, materials able to be shaped by spraying instead of by casting, e.g. gunite
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- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/0087—Uses not provided for elsewhere in C04B2111/00 for metallurgical applications
- C04B2111/00887—Ferrous metallurgy
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
- C04B2235/3206—Magnesium oxides or oxide-forming salts thereof
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B2235/9669—Resistance against chemicals, e.g. against molten glass or molten salts
- C04B2235/9676—Resistance against chemicals, e.g. against molten glass or molten salts against molten metals such as steel or aluminium
Abstract
REFRACTORY MATERIAL CONTAINING CALCIUM CARBONATE-STABILIZED SYNTHETIC DOLOMITE
Abstract A refractory material containing a synthetic dolomite aggregate having a calciumcarbonate coating on the surface thereof and further containing magnesia, a binder, a plasticizer, an organic fiber homogenizer, a bond stabilizer, and a dispersant; and a method of forming a protective refractory surface on the lining of a tundish, steel ladle and the like by spraying, gunning or troweling the surface coated aggregate containing refractory material thereon are disclosed. This material offers the multiple advantages of improving resistance to slaking, reducing alumina inclusions in the steel, and reducing clogging of the tundish nozzle.
Abstract A refractory material containing a synthetic dolomite aggregate having a calciumcarbonate coating on the surface thereof and further containing magnesia, a binder, a plasticizer, an organic fiber homogenizer, a bond stabilizer, and a dispersant; and a method of forming a protective refractory surface on the lining of a tundish, steel ladle and the like by spraying, gunning or troweling the surface coated aggregate containing refractory material thereon are disclosed. This material offers the multiple advantages of improving resistance to slaking, reducing alumina inclusions in the steel, and reducing clogging of the tundish nozzle.
Description
REFRACTORY MATERIAL CONTAlNli'~lG CALCiUM CARBONATE-STABILIZED SYNTHETIC DOLOMiTE
Backqround of the Invention The present invention relates to a refractory material, including sprayable material, gunnable material, and trowelable material, to be used principally for coatiny the surface of the back-up lining of a continuous casting tundish, steel ladle, and the like.
Conventionally, refractory rnaterial capable of being applied as a coating by spraying, gunning, or troweling, has been used for repairing the surface of a continuous castin~ tundish, steel ladle, and the like. Refractory materials using an aggregate of magnesia are generally used in such a coating refractory, but refractory materials using an aggregate of calcia such as lime and dolomite are known as well.
When a basic refractory containing a calcia aggregate is used in a tundish, CaO
in the aggregate selectively adsorbs, or as it is termed in the art, ~catches'', alumina and other non-metallic irnpurities which are contained in molten steel an~ which have a detrimental effect on final steel quality. The relative ability of a calcia-containing refractory to remove alumina and other impurities is referred to as the ~catch capability~
of the re~ractory. Reduction in the amount of these impurities also significantly reduces the occurrence of clogging in the tundish nozle caused by the deposition of impurities on the inner surface wall of the nozle. This s;elective catching property of CaO is metallurgically beneficial in that it results in higher purity steel.
However, when reffactory material using a calcia aggreg~te is applied to the inner sur~ace of tundishes and steei ladles, by any of the methods ot sp~aying, gunning, or troweling, all of which require the use of water, cracks may be generated andmaterial flaking or spalling may occur due to CaO in the aggregate reacting with the water (i.e. slaking~ during subsequent curing, drying or preheating. Accordingly, the application of calcia-aggregate containing refractory material is currently limited to use in non-aqueous systems.
The objective of the present invention is to provide a refractory material, which can be applied by any of the methods of spraying, gunning or troweling, to a tundish or steel ladle, in either a hot or cold state, and even in a situation where water is used.
This is aohieved in the present invention by including in the refractory a specific synthetic dolomite aggreyate having an excell0nt slaking resistance.
9 ~
Surnma of the Invention The refractory material for tundishes and steel ladles according to the present invention comprises from about 30 to about 90 % by weight of an aggregate of stabilized synthetic dolomite containing at least 30 % by weight of CaO. This stabilized 5 synthetic dolomite aggregate has a coating layer of CaC03 on its surface and has a particla size of up to about 10 rnm. Advantages of using the refractory composition of the present invention include improving tha resistance to slakiny, reducin~ the alumina content in the metal, and reducing the occurrence of clogging in the tundish nozzle.
Brief Descriotion of the Drawinqs Fig. 1 is a comparative p10t of alumina catch for the present refractory material d a conventional refractory material.
Fig. 2 is a comparative plot of alumina inclusion in rnetal processed through tundishes lined with the refractory rnaterial of the present invention and a conventional refractory material.
Detailed DescriPtion of the Invention The refractory material ~or tundishes, steel ladles, and the like according to the present invention, is mainly used as a sprayable material, gunnable material or a trowelable material. The composition of the material is modi~lable according to the rnethod ot application. The refractory material is composed of an aggregate, a binding material, a plasticizer, a homogenizer, a bond stabilizer and a dispersionlwetting agent.
The aggregate is a specific synthetic doiomite which has been treated with carbonate gas to form a surface coating of calcium carbonate thereon. This synthetic dolornite which has been subJected to such suriac0 treatment, contains 30 - 95 % by weight of CaO. When the synthetic dolomite has a CaO content less than 30 % by weight, the accornpanying metallurgical benefits, which occur in steelmaking due to the catching of alumina and other non-metallic irnpurities, is not satisfactorily exhib-lted.
However, if the calcium carbonate coated synthetic dolomite has a CaO content greater than 9S 56 by weight, the metallurgical benefits of a high GaO content are of~set by the material ha~ing a poorer resistance to slaking.
A synthetic dolomite having a particle size greater than about 0.04 mm and less than about 10 mm is used, with from about 0.04 mm to about 5 rnm being preferred.
For application as a spraying or gunning material, the preferred optirnum particle size of the synthetic dolomite is 3 mm or less. This is to suppress rebound loss when the materiai is applied. The preferred optimurn particle size for application as a trowelled material is 5 mm or less. A larger particle size material can be utilized in the trowellable application because the kneading step perforrned when preparing a trowelable material with a mixer imparts sufficient viscosity and flexibility to the material desplts the larger particle size. Therefore, materiai initially havin9 a coarse particle size can be used in 5 a trowelable material. In fact, excellent performance as to durability is obtained through the use of ¢oarse synthetic dolomite particlas in a trowelable material. The principal reason that the particle size of the synthetic dolomite is 5pecifled as 0.04 mm or coarser is because finer particles have a larger surface area which is detrimental to the slaking resistance of the material. The slaking resistance of a refractory material 10 containing particles flner than 0.~ mm is not improved, even alter treatment with gaseous CO2 to form a carbonate coating on the particles.
The calcium carbonate coated synthetic dolomite is manufactured by subjecting a synthetic dolomite aggregate to an atmosphere havin~ a CO2 concentration of 80%
or more, at a temperature of from about 400 to about 800 C, for from about 3 to about 15 6 hours. During this process, the surface of the synthetic dolomite conlacts and reacts with CO2 to forrn a coating layer of CaCO3. The process variables of CO2 concentration, temperature and treatment time may be modified, depending on the aggregate to be coated. The thickness of the CaCO3 coating layer on synthetic dolomite is from about 0.4 to about 1.0 ~Irn, with fr~m about 0.~ to about 1.0 IJm being 20 preferred.
The above surface coating process is preferably carried out after preparing the synt'netio dolomite having a particle size suitable for use as an aggregate in the product formulation for the refractory material. This is to prevent the exposure of uncoated, fresh surface, which is formed upon milling, grinding or pulverizing. Uncoated fresh 25 aggregate surface introduces hydration problems and consequently reducesthe slaking resistance of the malerial.
The CaCO3 coated synthetic dolomite rnay be compounded with other basic aggregates, for example, sea water magnesia, natural ma9nesia and olivine. In particular, the compoundin9 of magnesia having a particle size of up to about 0.04 rnm 30 with the synthetic dolomite is prcferred. This is due to synthetic dolomite having a particle size of up to about 0.04 mm exhibitin9 excessively lar9e 5urface area, which is not suitable in this application. The compounding aggregate is added to the dolomite in an arnount of from 0 to about 65% by weight in the re~ractory material. In add~ion to an asgregate, refractory material according to the present invention contains up to 7 ~
about 5.0 weight percent of a hornogenizer in the form of an organic fiber; up to about 6.0 weight percent of a binder, which binds with the refractory material, the binder being selected frorn the group consisting of alkali metaJ silicates, alkali metal phosphates, and combinations thereof, with sodium silicate and monosodium phospha~e belng preferred;
up to about 5.0 weight percent of a plasticizer, which enhances the ability of the refractory material t9 adhere to the surface to which it is applied, the plasticizer being selected trom the group consisting of a clay, such as bentonite or ball clay, a silica powder, and mixtures thereo~; up to about 5.0 weight percent of a bond stabiiizer, the bond stabilizer being at least one of an organic acid, preferably an aliphatic di- or tri-carboxylic, more preferably, an organic acid seleGted from the group consisting of tartaric, citric, oxalic, and malic acids, and mixtures thereof, or calcium carbonate; and up to 1.0 weight percent of a dispersion/wetting agent, preferably a lignin calcium sulphonate.
According to the present invention, a refractory material contains from about 30to about 90% by weight of the CaCO3 coated/stabilized synthetic dolomite aggregate.
The metallurgical benefits of this refracto7y material for a tundish or steel ladle are not ~ully achieved in a situation where there is less than 30% by weight of the stabilized synthetic dolomite aygregate. In contrast, a refractory material, containing more than 90% by weight of the synthetic dolomite aggregate, causes difficulty because of reduced slaking resistance of the material.
Refractory material of the present invention possesses remarkably improved slaking resistance compared with conventional refractory material. This is because the CaCO3 synthetic dolomite aggregate is stable when in contact with water. The coating layer of CaCo3 on the aggregate gives a high slaking resistance.
Therefore, the present refractory rnaterial can be used as a trowelable material, sprayable or gunnable material, even though water is added thereto for application by any of those means. In addition, the refractory material of the present invention can be applied to either a hot or cold surface, with no cracking or material flaking occurring E~ecause the surface refractory material contains a CaCO3-based synthetic dolomite aggregate, the metallurgical benefits in the purification of steel, such as the ability to catch alumina and other norl-metallic impurities from the molten steel are fully realized. Particulate impurities in the molten steel, known as ~inclusions,' such as alumina and other non-metallic impurities, which clog a tundish no~le are dramatically reduced by the use of the refractory rnaterial of the present invention, as compared with the use of a convenUonal refractory material.
Example~
The present invention can be more fully understood by the following examples, 5 which are not intended to be in any way limiting of the scope of the invention, as set forth in tha claims.
A. Formulation of Refractory Material A sprayable refractory material of the present invention was prepared, followingthe compounding ratio shown helow:
CaLCC)3 coated synthetic dolomite aggregate product (CM45, manufactured by Shin-Nihon Chemical Industry, Co. Ltd.) Particle size of 1 to 3 mm 38% by weight 1~ Particle size less than 1 mm 27% by weight * Sea wa~er magnesia Particle size less than 0.04 mm 28.2% by weight Organic pulp fiber 1.7% by weight Sodium silicate (binder) 2.5% by weight * Malic acid (bond stabilizer) 0.6% by weight Bentonite (plasticizer) 2~0% by weight To 100 parts by weight of the above material was added 22 parts by weight of water. The resulting mixture was cold sprayed onto the surface of the back-up lining o~ a tundish to form a layer having a thickness of about 25 mm. No cracking or flaking 25 of the refractory material was observed upon subsequent air curing.
E~. Reduction in Tundish Nozz!e Clo~
A comparative lest was made to demonstrate that use of the refractory material of the present invention as a tundish lining results in a reduction in tundish nozzle clogging and that there is an improvernent in operability, over use of a conventional 30 MgO clinker-based refractory material.
A tundish with a 20-ton capacity was cold-sprayed with the refractory material of the present invention, as in Pan A, to torm a removable refractory lining therein. The tundish was then preheated to a temperature of 2000F and placed in service in acontinuous casting station. A continuous sequence of five heats of molten steel, each 2 ~ ~ 9 ~
of 84 tons per heat, was then passed through the tundish, exiting through an exit nozzle in the tundish.
For comparative purposes, the above sequenca was repeated using a tundish coated with a lining rnade of a conventional MgO clinker-based material.
6 After completion of all five heats, the tundishes were removed from service and cooled. A chemical and X-ray diffraction analysis of the impurity-containing substance deposited on the inside surface of the nozzle, which ranged in thickness o7 from O to 10 mm on the nozzle of the tundish lined with the refractory material of the present invention, but was signffllcantly thicker, up to about 25 mm, on the surface of the nozzle 10 of the tundish lined with a conventional refractory material, was made for both the tundishes. The chemical composition and relative presence of various mineral compounds, as disclosed by X-ray diffraction of lhe deposits in both tundish nozzles, is shown in Table 1.
Table î. Chemical and mineral analysls of deposits in the tundish nozzle _ _ _ _ _ Present Refi actory ConveDtional MgO Clinker Material Based Material I __ _._ _ _ Chem;cal Com~osition (%) 2.5 7.7 :20 SiO2 78.3 82.5 Fe2O~ 15.7 4.2 Minerals (Relative pres~nce~
~ 03 ~ + + +
MgOGAI20, + +++
CaO-6AI20, + O
CaO2AI20, + O
1 3CaO~5Al20~ _ _ + _ ---As is seen from Table 1, the refractory material of the present invention causesa reduction in the alumina inclusion in the metal, as indicated by the lower aiumina chemical content in the deposit (78.3% versus 82.5% for the conventional refractory 35 material). This is due to the hi~h reactivity of alumina with CaO in the refractory The calcium aluminate phases formed in the retractory of the present invention are mineral complex species with lower melting points than alurnina itself, and magnesium alumin~e, which are the only species formed in the conventional MgO clinker-based refractory. These complexes more readily penetrate the refractory material of the 7 ~
present invention, thereby giving it a greater alumina catch capability. These additional alumina - containin~ species ara not formed with conventional M~O clinker based re~ractory material.
This comparative test demonstrated that use of the refractory material of the 5 present invention signi~lcantly reduces the occurrence of deposition of occluding maffer in the tundish nozzle (deposited matter, namely, non-metallic 'inciusion~, principally cornprising alumina), as compared with the use of conventional sprayed refractory rnaterial.
C. Increased Aiumina Catch Capabilitv of Refractory Material and Reduction of Alumina Inclusion in Metal A comparative test was made to demonstrate the incrsase in the alumina catch capability of the refractory material of the present invention over convsntional MgO
clinker-based refractory and to show that use of the present refractory material results in the production of a better grade metal due to a reduction of aiumina inclusion in the 1 5 metal.
A tundish with a 50-ton capacity was cold-sprayed with the refractory material o~ the present invention, as in Part A, to form a removable refractory lining therein. The tundish was then preheated to a temperature of 2000F and placed in service in acontinuous casting station. A continuous sequence of four heats of molten steel, each 20 of 250 tons per heat, was then passed through the tundish, exiting through an exit nozzle in the tundish.
For comparative purposes, the above sequence was repeated using a tundish coated with a lining made of conventional MgO clinker-based material.
~ fter each heat, a sample of the molten metal in the tundish was removed for 2S analysis for alumina inclusion. The comparative results for each heat, for both the present refractory material and the conventional refractory material, are shown in Fig.
1. As is seen from Fig. 1, the amount of alumina inclusion in the rnetal is significantly lower in each heat for the tundish which was lined with the refractory rnaterial of the present invention, than for the tundish which was lined with the conventional MgO
30 clinker-based refractory.
After completion of all four heats, the tundishes were removed from service and cooled. The refractory linings were removed and analyzed for alumina catch. The comparative re~ults are shown in Table 2 and Fig. 2.
Table 2. Chemical analysls oi refractonf rnaterial~ after u8e ¦Pre~ent Refraotory ~Conventional MgO Clinker iMateri~l ¦ Ba~ed Mat~rial i ~ ~ _ , Distance from sur~ac~ (mm) l I _ , _ _ I
Chemical Comvosition (%~ 5 1 10 15 1 20 5 t0 15 20 MgO 39 .9 47.3 53 .3 65 .3 69 .175 .3 81.079.2 CaO 11.4 28.9 30.7 25.1 7.3 4.1 2.1 2.8 SiO2 2.8 6.5 7.3 6.1 9.2 9.5 8.111.1 A120~ 8.1 9.d, 5.9 1.6 8.3 5.0 3.2 2.3 Fe2O, 31.4 3.0 0.8 0.3 3.2 3.0 2.7 2.0 _ == = _ = ___ As seen from Table 2 and Fig. 2, the amount of Al2O3 catch in the refractory material, measured at several penetrative distances from the outer surface of the lining exposed to the molten metal was substantially higher at penetr~tive distances of from 15 about 7 to about 15 mm for the refractory, thereby demonstrating the superior alumina catch capability of the refractory materiaî of the present invention over conventional material.
D. Conclusion The refractory material of the present invention reduces tundish nozzle cloggingand reduces the amount of undesirable alumina inclusion in the metal. ~IVithout wishing to be limited to a particular explanation of the effectiveness of the refractory material of the present invention in accomplishing this, one reason is believed to be that alumina suspended in the molten metal reacts with CaO in the refractory material of the present invention and lorms calcium aluminates, which have lower melting points than alumina and magnesium aluminate. These calcium alurninates are beffer able to penetrate into the refractory material, expressed as a higher equivalent alurnina catch capability of the refractory material of the present invention. In combination with this effect, the calcium aluminates are lighter than the alumina and float to the surface of the molten metal bath where they can be skimmed-off. Together, both of these effects ~unction to reduce the amount ~ alumina inclusion in the metal and the extent of alumina deposits in the tundish nozzle.
9 ~ ~ ~
ExamE~le 2 A trowelable refractory material of the present invention was prepared, following the compounding ratio shown below.
CaC03 coated synthetic dolomite aggregate product (CM45, manufactured by 5 Shin-Nihon Chemical Industry, Co. Ud.) Particle size of 30 to 5 mm 159~ by weight Particle 5ize of 10 to 3 mm 15% by weight Particle size less than 1 mm 34% by weight * Sea water magnesia Particle size less than 0.04 mm 27% by weight * CaCO3 ~bond stabilizer) 5% by weight * Silica powder ~plasticizer) 2% by weight * Monobasic sodium phosphate (binder) 0.2% by weight * Lignin calcium sulphonate (dispersanVwetting agent) 0.2% by weight (P-~01, manufactured by Sanyo Kokusaku Pulpl Co. Ltd) * Organic pulp fiber (homogenker) 1.6% by weight The trowelable material comprising the ab~ve ingredients was cold-trowelled 20 onto the face of the lining base material of a tundish, to form a coating layer of a thickness of about 25 rnm. When the obtainecl coating layer was examined, no cracking or material flaking of the coating was observed, indicating the excellent condition of the coating.
Backqround of the Invention The present invention relates to a refractory material, including sprayable material, gunnable material, and trowelable material, to be used principally for coatiny the surface of the back-up lining of a continuous casting tundish, steel ladle, and the like.
Conventionally, refractory rnaterial capable of being applied as a coating by spraying, gunning, or troweling, has been used for repairing the surface of a continuous castin~ tundish, steel ladle, and the like. Refractory materials using an aggregate of magnesia are generally used in such a coating refractory, but refractory materials using an aggregate of calcia such as lime and dolomite are known as well.
When a basic refractory containing a calcia aggregate is used in a tundish, CaO
in the aggregate selectively adsorbs, or as it is termed in the art, ~catches'', alumina and other non-metallic irnpurities which are contained in molten steel an~ which have a detrimental effect on final steel quality. The relative ability of a calcia-containing refractory to remove alumina and other impurities is referred to as the ~catch capability~
of the re~ractory. Reduction in the amount of these impurities also significantly reduces the occurrence of clogging in the tundish nozle caused by the deposition of impurities on the inner surface wall of the nozle. This s;elective catching property of CaO is metallurgically beneficial in that it results in higher purity steel.
However, when reffactory material using a calcia aggreg~te is applied to the inner sur~ace of tundishes and steei ladles, by any of the methods ot sp~aying, gunning, or troweling, all of which require the use of water, cracks may be generated andmaterial flaking or spalling may occur due to CaO in the aggregate reacting with the water (i.e. slaking~ during subsequent curing, drying or preheating. Accordingly, the application of calcia-aggregate containing refractory material is currently limited to use in non-aqueous systems.
The objective of the present invention is to provide a refractory material, which can be applied by any of the methods of spraying, gunning or troweling, to a tundish or steel ladle, in either a hot or cold state, and even in a situation where water is used.
This is aohieved in the present invention by including in the refractory a specific synthetic dolomite aggreyate having an excell0nt slaking resistance.
9 ~
Surnma of the Invention The refractory material for tundishes and steel ladles according to the present invention comprises from about 30 to about 90 % by weight of an aggregate of stabilized synthetic dolomite containing at least 30 % by weight of CaO. This stabilized 5 synthetic dolomite aggregate has a coating layer of CaC03 on its surface and has a particla size of up to about 10 rnm. Advantages of using the refractory composition of the present invention include improving tha resistance to slakiny, reducin~ the alumina content in the metal, and reducing the occurrence of clogging in the tundish nozzle.
Brief Descriotion of the Drawinqs Fig. 1 is a comparative p10t of alumina catch for the present refractory material d a conventional refractory material.
Fig. 2 is a comparative plot of alumina inclusion in rnetal processed through tundishes lined with the refractory rnaterial of the present invention and a conventional refractory material.
Detailed DescriPtion of the Invention The refractory material ~or tundishes, steel ladles, and the like according to the present invention, is mainly used as a sprayable material, gunnable material or a trowelable material. The composition of the material is modi~lable according to the rnethod ot application. The refractory material is composed of an aggregate, a binding material, a plasticizer, a homogenizer, a bond stabilizer and a dispersionlwetting agent.
The aggregate is a specific synthetic doiomite which has been treated with carbonate gas to form a surface coating of calcium carbonate thereon. This synthetic dolornite which has been subJected to such suriac0 treatment, contains 30 - 95 % by weight of CaO. When the synthetic dolomite has a CaO content less than 30 % by weight, the accornpanying metallurgical benefits, which occur in steelmaking due to the catching of alumina and other non-metallic irnpurities, is not satisfactorily exhib-lted.
However, if the calcium carbonate coated synthetic dolomite has a CaO content greater than 9S 56 by weight, the metallurgical benefits of a high GaO content are of~set by the material ha~ing a poorer resistance to slaking.
A synthetic dolomite having a particle size greater than about 0.04 mm and less than about 10 mm is used, with from about 0.04 mm to about 5 rnm being preferred.
For application as a spraying or gunning material, the preferred optirnum particle size of the synthetic dolomite is 3 mm or less. This is to suppress rebound loss when the materiai is applied. The preferred optimurn particle size for application as a trowelled material is 5 mm or less. A larger particle size material can be utilized in the trowellable application because the kneading step perforrned when preparing a trowelable material with a mixer imparts sufficient viscosity and flexibility to the material desplts the larger particle size. Therefore, materiai initially havin9 a coarse particle size can be used in 5 a trowelable material. In fact, excellent performance as to durability is obtained through the use of ¢oarse synthetic dolomite particlas in a trowelable material. The principal reason that the particle size of the synthetic dolomite is 5pecifled as 0.04 mm or coarser is because finer particles have a larger surface area which is detrimental to the slaking resistance of the material. The slaking resistance of a refractory material 10 containing particles flner than 0.~ mm is not improved, even alter treatment with gaseous CO2 to form a carbonate coating on the particles.
The calcium carbonate coated synthetic dolomite is manufactured by subjecting a synthetic dolomite aggregate to an atmosphere havin~ a CO2 concentration of 80%
or more, at a temperature of from about 400 to about 800 C, for from about 3 to about 15 6 hours. During this process, the surface of the synthetic dolomite conlacts and reacts with CO2 to forrn a coating layer of CaCO3. The process variables of CO2 concentration, temperature and treatment time may be modified, depending on the aggregate to be coated. The thickness of the CaCO3 coating layer on synthetic dolomite is from about 0.4 to about 1.0 ~Irn, with fr~m about 0.~ to about 1.0 IJm being 20 preferred.
The above surface coating process is preferably carried out after preparing the synt'netio dolomite having a particle size suitable for use as an aggregate in the product formulation for the refractory material. This is to prevent the exposure of uncoated, fresh surface, which is formed upon milling, grinding or pulverizing. Uncoated fresh 25 aggregate surface introduces hydration problems and consequently reducesthe slaking resistance of the malerial.
The CaCO3 coated synthetic dolomite rnay be compounded with other basic aggregates, for example, sea water magnesia, natural ma9nesia and olivine. In particular, the compoundin9 of magnesia having a particle size of up to about 0.04 rnm 30 with the synthetic dolomite is prcferred. This is due to synthetic dolomite having a particle size of up to about 0.04 mm exhibitin9 excessively lar9e 5urface area, which is not suitable in this application. The compounding aggregate is added to the dolomite in an arnount of from 0 to about 65% by weight in the re~ractory material. In add~ion to an asgregate, refractory material according to the present invention contains up to 7 ~
about 5.0 weight percent of a hornogenizer in the form of an organic fiber; up to about 6.0 weight percent of a binder, which binds with the refractory material, the binder being selected frorn the group consisting of alkali metaJ silicates, alkali metal phosphates, and combinations thereof, with sodium silicate and monosodium phospha~e belng preferred;
up to about 5.0 weight percent of a plasticizer, which enhances the ability of the refractory material t9 adhere to the surface to which it is applied, the plasticizer being selected trom the group consisting of a clay, such as bentonite or ball clay, a silica powder, and mixtures thereo~; up to about 5.0 weight percent of a bond stabiiizer, the bond stabilizer being at least one of an organic acid, preferably an aliphatic di- or tri-carboxylic, more preferably, an organic acid seleGted from the group consisting of tartaric, citric, oxalic, and malic acids, and mixtures thereof, or calcium carbonate; and up to 1.0 weight percent of a dispersion/wetting agent, preferably a lignin calcium sulphonate.
According to the present invention, a refractory material contains from about 30to about 90% by weight of the CaCO3 coated/stabilized synthetic dolomite aggregate.
The metallurgical benefits of this refracto7y material for a tundish or steel ladle are not ~ully achieved in a situation where there is less than 30% by weight of the stabilized synthetic dolomite aygregate. In contrast, a refractory material, containing more than 90% by weight of the synthetic dolomite aggregate, causes difficulty because of reduced slaking resistance of the material.
Refractory material of the present invention possesses remarkably improved slaking resistance compared with conventional refractory material. This is because the CaCO3 synthetic dolomite aggregate is stable when in contact with water. The coating layer of CaCo3 on the aggregate gives a high slaking resistance.
Therefore, the present refractory rnaterial can be used as a trowelable material, sprayable or gunnable material, even though water is added thereto for application by any of those means. In addition, the refractory material of the present invention can be applied to either a hot or cold surface, with no cracking or material flaking occurring E~ecause the surface refractory material contains a CaCO3-based synthetic dolomite aggregate, the metallurgical benefits in the purification of steel, such as the ability to catch alumina and other norl-metallic impurities from the molten steel are fully realized. Particulate impurities in the molten steel, known as ~inclusions,' such as alumina and other non-metallic impurities, which clog a tundish no~le are dramatically reduced by the use of the refractory rnaterial of the present invention, as compared with the use of a convenUonal refractory material.
Example~
The present invention can be more fully understood by the following examples, 5 which are not intended to be in any way limiting of the scope of the invention, as set forth in tha claims.
A. Formulation of Refractory Material A sprayable refractory material of the present invention was prepared, followingthe compounding ratio shown helow:
CaLCC)3 coated synthetic dolomite aggregate product (CM45, manufactured by Shin-Nihon Chemical Industry, Co. Ltd.) Particle size of 1 to 3 mm 38% by weight 1~ Particle size less than 1 mm 27% by weight * Sea wa~er magnesia Particle size less than 0.04 mm 28.2% by weight Organic pulp fiber 1.7% by weight Sodium silicate (binder) 2.5% by weight * Malic acid (bond stabilizer) 0.6% by weight Bentonite (plasticizer) 2~0% by weight To 100 parts by weight of the above material was added 22 parts by weight of water. The resulting mixture was cold sprayed onto the surface of the back-up lining o~ a tundish to form a layer having a thickness of about 25 mm. No cracking or flaking 25 of the refractory material was observed upon subsequent air curing.
E~. Reduction in Tundish Nozz!e Clo~
A comparative lest was made to demonstrate that use of the refractory material of the present invention as a tundish lining results in a reduction in tundish nozzle clogging and that there is an improvernent in operability, over use of a conventional 30 MgO clinker-based refractory material.
A tundish with a 20-ton capacity was cold-sprayed with the refractory material of the present invention, as in Pan A, to torm a removable refractory lining therein. The tundish was then preheated to a temperature of 2000F and placed in service in acontinuous casting station. A continuous sequence of five heats of molten steel, each 2 ~ ~ 9 ~
of 84 tons per heat, was then passed through the tundish, exiting through an exit nozzle in the tundish.
For comparative purposes, the above sequenca was repeated using a tundish coated with a lining rnade of a conventional MgO clinker-based material.
6 After completion of all five heats, the tundishes were removed from service and cooled. A chemical and X-ray diffraction analysis of the impurity-containing substance deposited on the inside surface of the nozzle, which ranged in thickness o7 from O to 10 mm on the nozzle of the tundish lined with the refractory material of the present invention, but was signffllcantly thicker, up to about 25 mm, on the surface of the nozzle 10 of the tundish lined with a conventional refractory material, was made for both the tundishes. The chemical composition and relative presence of various mineral compounds, as disclosed by X-ray diffraction of lhe deposits in both tundish nozzles, is shown in Table 1.
Table î. Chemical and mineral analysls of deposits in the tundish nozzle _ _ _ _ _ Present Refi actory ConveDtional MgO Clinker Material Based Material I __ _._ _ _ Chem;cal Com~osition (%) 2.5 7.7 :20 SiO2 78.3 82.5 Fe2O~ 15.7 4.2 Minerals (Relative pres~nce~
~ 03 ~ + + +
MgOGAI20, + +++
CaO-6AI20, + O
CaO2AI20, + O
1 3CaO~5Al20~ _ _ + _ ---As is seen from Table 1, the refractory material of the present invention causesa reduction in the alumina inclusion in the metal, as indicated by the lower aiumina chemical content in the deposit (78.3% versus 82.5% for the conventional refractory 35 material). This is due to the hi~h reactivity of alumina with CaO in the refractory The calcium aluminate phases formed in the retractory of the present invention are mineral complex species with lower melting points than alurnina itself, and magnesium alumin~e, which are the only species formed in the conventional MgO clinker-based refractory. These complexes more readily penetrate the refractory material of the 7 ~
present invention, thereby giving it a greater alumina catch capability. These additional alumina - containin~ species ara not formed with conventional M~O clinker based re~ractory material.
This comparative test demonstrated that use of the refractory material of the 5 present invention signi~lcantly reduces the occurrence of deposition of occluding maffer in the tundish nozzle (deposited matter, namely, non-metallic 'inciusion~, principally cornprising alumina), as compared with the use of conventional sprayed refractory rnaterial.
C. Increased Aiumina Catch Capabilitv of Refractory Material and Reduction of Alumina Inclusion in Metal A comparative test was made to demonstrate the incrsase in the alumina catch capability of the refractory material of the present invention over convsntional MgO
clinker-based refractory and to show that use of the present refractory material results in the production of a better grade metal due to a reduction of aiumina inclusion in the 1 5 metal.
A tundish with a 50-ton capacity was cold-sprayed with the refractory material o~ the present invention, as in Part A, to form a removable refractory lining therein. The tundish was then preheated to a temperature of 2000F and placed in service in acontinuous casting station. A continuous sequence of four heats of molten steel, each 20 of 250 tons per heat, was then passed through the tundish, exiting through an exit nozzle in the tundish.
For comparative purposes, the above sequence was repeated using a tundish coated with a lining made of conventional MgO clinker-based material.
~ fter each heat, a sample of the molten metal in the tundish was removed for 2S analysis for alumina inclusion. The comparative results for each heat, for both the present refractory material and the conventional refractory material, are shown in Fig.
1. As is seen from Fig. 1, the amount of alumina inclusion in the rnetal is significantly lower in each heat for the tundish which was lined with the refractory rnaterial of the present invention, than for the tundish which was lined with the conventional MgO
30 clinker-based refractory.
After completion of all four heats, the tundishes were removed from service and cooled. The refractory linings were removed and analyzed for alumina catch. The comparative re~ults are shown in Table 2 and Fig. 2.
Table 2. Chemical analysls oi refractonf rnaterial~ after u8e ¦Pre~ent Refraotory ~Conventional MgO Clinker iMateri~l ¦ Ba~ed Mat~rial i ~ ~ _ , Distance from sur~ac~ (mm) l I _ , _ _ I
Chemical Comvosition (%~ 5 1 10 15 1 20 5 t0 15 20 MgO 39 .9 47.3 53 .3 65 .3 69 .175 .3 81.079.2 CaO 11.4 28.9 30.7 25.1 7.3 4.1 2.1 2.8 SiO2 2.8 6.5 7.3 6.1 9.2 9.5 8.111.1 A120~ 8.1 9.d, 5.9 1.6 8.3 5.0 3.2 2.3 Fe2O, 31.4 3.0 0.8 0.3 3.2 3.0 2.7 2.0 _ == = _ = ___ As seen from Table 2 and Fig. 2, the amount of Al2O3 catch in the refractory material, measured at several penetrative distances from the outer surface of the lining exposed to the molten metal was substantially higher at penetr~tive distances of from 15 about 7 to about 15 mm for the refractory, thereby demonstrating the superior alumina catch capability of the refractory materiaî of the present invention over conventional material.
D. Conclusion The refractory material of the present invention reduces tundish nozzle cloggingand reduces the amount of undesirable alumina inclusion in the metal. ~IVithout wishing to be limited to a particular explanation of the effectiveness of the refractory material of the present invention in accomplishing this, one reason is believed to be that alumina suspended in the molten metal reacts with CaO in the refractory material of the present invention and lorms calcium aluminates, which have lower melting points than alumina and magnesium aluminate. These calcium alurninates are beffer able to penetrate into the refractory material, expressed as a higher equivalent alurnina catch capability of the refractory material of the present invention. In combination with this effect, the calcium aluminates are lighter than the alumina and float to the surface of the molten metal bath where they can be skimmed-off. Together, both of these effects ~unction to reduce the amount ~ alumina inclusion in the metal and the extent of alumina deposits in the tundish nozzle.
9 ~ ~ ~
ExamE~le 2 A trowelable refractory material of the present invention was prepared, following the compounding ratio shown below.
CaC03 coated synthetic dolomite aggregate product (CM45, manufactured by 5 Shin-Nihon Chemical Industry, Co. Ud.) Particle size of 30 to 5 mm 159~ by weight Particle 5ize of 10 to 3 mm 15% by weight Particle size less than 1 mm 34% by weight * Sea water magnesia Particle size less than 0.04 mm 27% by weight * CaCO3 ~bond stabilizer) 5% by weight * Silica powder ~plasticizer) 2% by weight * Monobasic sodium phosphate (binder) 0.2% by weight * Lignin calcium sulphonate (dispersanVwetting agent) 0.2% by weight (P-~01, manufactured by Sanyo Kokusaku Pulpl Co. Ltd) * Organic pulp fiber (homogenker) 1.6% by weight The trowelable material comprising the ab~ve ingredients was cold-trowelled 20 onto the face of the lining base material of a tundish, to form a coating layer of a thickness of about 25 rnm. When the obtainecl coating layer was examined, no cracking or material flaking of the coating was observed, indicating the excellent condition of the coating.
Claims (8)
1. A refractory material for use in a tundish, steel ladle, and the like, comprising:
from about 30 to about 90 percent, based on the total weight of the material, ofa synthetic dolomite aggregate containing from about 30 to about 95 percent, based on the weight of dolomite, of calcium oxide, said dolomite having a particle size of from about 0.04 to about 5 mm, and a coating layer of calcium carbonate of from about 0.4 to about 1.0 µm on the surface thereof;
from 0 to about 65 percent, based on the total weight of the material, of magnesia;
from 0 to about 6 percent, based on the total weight of the material, of a binder selected from the group consisting of alkali metal silicates, alkali metal phosphates and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of a plasticizer selected from the group consisting of clay, silica powder, and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of an organic fiber homogenizer;
from 0 to about 6 percent, based on the total weight of the material, of a bond stabilizer selected from the group consisting of aliphatic di- and tri- carboxylic acid and mixtures thereof and calcium carbonate;
from 0 to about 1 percent, based on the total weight of the material, of a dispersant;
such that the refractory material is capable of being applied to a surface in a hot or a cold state; the refractory material exhibits good slaking resistance; and the refractory material exhibits good catch capability of both alumina and non-metallic impurities in molten material with which the refractory material comes into contact, thereby reducing the occurrence of clogging in nozzles and the like through which said molten material which has been in contact with the refractory material flows.
from about 30 to about 90 percent, based on the total weight of the material, ofa synthetic dolomite aggregate containing from about 30 to about 95 percent, based on the weight of dolomite, of calcium oxide, said dolomite having a particle size of from about 0.04 to about 5 mm, and a coating layer of calcium carbonate of from about 0.4 to about 1.0 µm on the surface thereof;
from 0 to about 65 percent, based on the total weight of the material, of magnesia;
from 0 to about 6 percent, based on the total weight of the material, of a binder selected from the group consisting of alkali metal silicates, alkali metal phosphates and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of a plasticizer selected from the group consisting of clay, silica powder, and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of an organic fiber homogenizer;
from 0 to about 6 percent, based on the total weight of the material, of a bond stabilizer selected from the group consisting of aliphatic di- and tri- carboxylic acid and mixtures thereof and calcium carbonate;
from 0 to about 1 percent, based on the total weight of the material, of a dispersant;
such that the refractory material is capable of being applied to a surface in a hot or a cold state; the refractory material exhibits good slaking resistance; and the refractory material exhibits good catch capability of both alumina and non-metallic impurities in molten material with which the refractory material comes into contact, thereby reducing the occurrence of clogging in nozzles and the like through which said molten material which has been in contact with the refractory material flows.
2. The refractory material according to claim 1 wherein:
the calcium carbonate-coated synthetic dolomite aggregate is 65.0 weight percent of the total material;
the magnesia is 28.2 weight percent of the total material;
the binder is sodium silicate and is 2.5 weight percent of the total material;
the plasticizer is bentonite clay and Is 2.0 weight percent of the total material;
the organic fiber homogenizer is a pulp and is 1.7 weight percent of the total material; and the bond stabilizer is malic acid and is 0.6 weight percent of the total material.
the calcium carbonate-coated synthetic dolomite aggregate is 65.0 weight percent of the total material;
the magnesia is 28.2 weight percent of the total material;
the binder is sodium silicate and is 2.5 weight percent of the total material;
the plasticizer is bentonite clay and Is 2.0 weight percent of the total material;
the organic fiber homogenizer is a pulp and is 1.7 weight percent of the total material; and the bond stabilizer is malic acid and is 0.6 weight percent of the total material.
3. The refractory material according to claim 1 wherein:
the calcium carbonate coated synthetic dolomite aggregate is 64.0 weight percent of the total material;
the magnesia is 27.0 weight percent of the total material;
the binder is monobasic sodium phosphate and is 0.2 weight percent of the total material;
the plasticizer is silica powder and is 2.0 weight percent of the total material;
the organic fiber homogenizer is a pulp and is 1.6 weight percent of the total material;
the bond stabilizer is calcium carbonate and is 5.0 weight percent of the total material; and the dispersant is lignin calcium sulphonate and is 0.2 weight percent of the total material.
the calcium carbonate coated synthetic dolomite aggregate is 64.0 weight percent of the total material;
the magnesia is 27.0 weight percent of the total material;
the binder is monobasic sodium phosphate and is 0.2 weight percent of the total material;
the plasticizer is silica powder and is 2.0 weight percent of the total material;
the organic fiber homogenizer is a pulp and is 1.6 weight percent of the total material;
the bond stabilizer is calcium carbonate and is 5.0 weight percent of the total material; and the dispersant is lignin calcium sulphonate and is 0.2 weight percent of the total material.
4. A method for protecting a lining material in a tundish, steel ladle and the like comprising applying to the surface of said lining a refractory material containing from about 30 to about 90 weight percent in the material of a synthetic dolomite aggregate containing from about 30 to about 95 weight percent, based on the dolomite, of calcium oxide, said dolomite having a particle grain size of from about 0.04 to about
5 mm, and a coating layer of calcium carbonate of from about 0.8 to about 1.0 µm on the surface thereof;
from 0 to about 65 percent, based on the total weight of the material, of magnesia;
from 0 to about 6 percent, based on the total weight of the material, of a binder selected from the group consisting of alkali metal silicates, alkali metal phosphates and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of a plasticizer selected from the group consisting of clay, silica powder, and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of an organic fiber homogenizer;
from 0 to about 5 percent, based on the total weight of the material, of a bond stabilizer selected from the group consisting of aliphatic di- and tri- carboxylic acid and mixtures thereof; and from 0 to about 1 percent, based on the total weight of the material, of a dispersant.
5. The method according to claim 4 wherein the refractory material is applied to the lining by means selected from the group consisting of gunning, spraying and troweling.
from 0 to about 65 percent, based on the total weight of the material, of magnesia;
from 0 to about 6 percent, based on the total weight of the material, of a binder selected from the group consisting of alkali metal silicates, alkali metal phosphates and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of a plasticizer selected from the group consisting of clay, silica powder, and mixtures thereof;
from 0 to about 5 percent, based on the total weight of the material, of an organic fiber homogenizer;
from 0 to about 5 percent, based on the total weight of the material, of a bond stabilizer selected from the group consisting of aliphatic di- and tri- carboxylic acid and mixtures thereof; and from 0 to about 1 percent, based on the total weight of the material, of a dispersant.
5. The method according to claim 4 wherein the refractory material is applied to the lining by means selected from the group consisting of gunning, spraying and troweling.
6. The refractory material according to claim 1, 2 or 3, wherein the coating layer of calcium carbonate of the synthetic dolomite has a thickness of from about 0.8 to about 1.0 µm.
7. The refractory material according to claim 1, which contains up to 65 percent of magnesia having a particle size of up to about 0.04 mm.
8. A process for manufacturing the refractory material as defined in any one of claims 1 to 3, which comprises:
subjecting a synthetic dolomite aggregate containing from about 30 to about 95 percent, based on the weight of the dolomite, of calcium oxide, the said dolomite having a particle size of from about 0.04 to about 5 mm, to an atmosphere having a CO2 concentration of 80 percent or more at a temperature of from about 400 to 800°C for a time sufficient to form a CaCO3 coating layer on the dolomite having a thickness of from about 0.4 to about 1.0 µm; and compounding the resulting CaCO3 coated dolomite aggregate with the other components.
subjecting a synthetic dolomite aggregate containing from about 30 to about 95 percent, based on the weight of the dolomite, of calcium oxide, the said dolomite having a particle size of from about 0.04 to about 5 mm, to an atmosphere having a CO2 concentration of 80 percent or more at a temperature of from about 400 to 800°C for a time sufficient to form a CaCO3 coating layer on the dolomite having a thickness of from about 0.4 to about 1.0 µm; and compounding the resulting CaCO3 coated dolomite aggregate with the other components.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP216179/90 | 1990-08-16 | ||
| JP2216179A JPH0822781B2 (en) | 1990-08-16 | 1990-08-16 | Surface coating for tundish and ladle ladle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2049171A1 true CA2049171A1 (en) | 1992-02-17 |
Family
ID=16684528
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002049171A Abandoned CA2049171A1 (en) | 1990-08-16 | 1991-08-14 | Surface coating material for tundish and steel ladle |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0472350B1 (en) |
| JP (1) | JPH0822781B2 (en) |
| KR (1) | KR940001661B1 (en) |
| AU (2) | AU8250791A (en) |
| BR (1) | BR9103497A (en) |
| CA (1) | CA2049171A1 (en) |
| DE (1) | DE69114412T2 (en) |
| ES (1) | ES2082929T3 (en) |
| HK (1) | HK1007734A1 (en) |
| ZA (1) | ZA916453B (en) |
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| US8236720B2 (en) | 2007-07-14 | 2012-08-07 | Refractory Intellectual Property Gmbh & Co. Kg | Unshaped refractory material, a process for producing an earth-moist, unshaped refractory material, and use of the unshaped refractory material |
| CN115229139A (en) * | 2022-06-15 | 2022-10-25 | 攀钢集团攀枝花钢铁研究院有限公司 | Heavy rail steel continuous casting tundish covering agent and adding method thereof |
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| US5766686A (en) * | 1996-03-01 | 1998-06-16 | North American Refractories Co. | Spray insulating coating for refractory articles |
| US6537486B1 (en) * | 2000-03-17 | 2003-03-25 | Yesuvius Crucible Company | Anti-buildup liner |
| KR100484538B1 (en) * | 2002-08-01 | 2005-04-20 | 주식회사 포스렉 | Agent for Coating Pernament Lining of Hot Vessel |
| ES2366562T3 (en) * | 2005-08-30 | 2011-10-21 | REFRACTORY INTELLECTUAL PROPERTY GMBH & CO. KG | PROCEDURE FOR THE MANUFACTURE OF A REFRACTORY CERAMIC PRODUCT. |
| CN102910631A (en) * | 2012-09-21 | 2013-02-06 | 福建省上杭县九洲硅业有限公司 | Preparation method of silica micropowder-carbon composite raw material used for smelting industrial silicon |
| DE102021006060A1 (en) | 2021-12-08 | 2023-06-15 | Technische Universität Bergakademie Freiberg, Körperschaft des öffentlichen Rechts | Process and binder system for the production of components based on ceramics, metals and metal-ceramic composites using the binder jetting 3D process |
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| EP0123755A1 (en) * | 1983-04-19 | 1984-11-07 | Aikoh Co. Ltd. | Unshaped and refractory composition for coating or filling |
| JPS6090858A (en) * | 1983-10-21 | 1985-05-22 | フアイザー・クイグレー株式会社 | Digestion-resistant refractory aggregate containing free lime and manufacture |
| GB8510143D0 (en) * | 1985-04-20 | 1985-05-30 | Foseco Trading Ag | Pouring tubes |
| FR2643631B1 (en) * | 1989-02-27 | 1993-02-12 | Lorraine Laminage | REFRACTORY COATING OF CONTINUOUS CASTING DISTRIBUTOR OF METALS |
| JPH03126678A (en) * | 1989-10-06 | 1991-05-29 | Harima Ceramic Co Ltd | Casting monolithic refractory for lining molten metal vessel |
| JPH03193672A (en) * | 1989-12-20 | 1991-08-23 | Harima Ceramic Co Ltd | Coating material and weir for tundish |
-
1990
- 1990-08-16 JP JP2216179A patent/JPH0822781B2/en not_active Expired - Lifetime
-
1991
- 1991-08-13 ES ES91307480T patent/ES2082929T3/en not_active Expired - Lifetime
- 1991-08-13 DE DE69114412T patent/DE69114412T2/en not_active Expired - Fee Related
- 1991-08-13 EP EP91307480A patent/EP0472350B1/en not_active Expired - Lifetime
- 1991-08-14 CA CA002049171A patent/CA2049171A1/en not_active Abandoned
- 1991-08-15 ZA ZA916453A patent/ZA916453B/en unknown
- 1991-08-15 BR BR919103497A patent/BR9103497A/en not_active IP Right Cessation
- 1991-08-15 AU AU82507/91A patent/AU8250791A/en not_active Abandoned
- 1991-08-16 KR KR1019910014136A patent/KR940001661B1/en not_active IP Right Cessation
-
1994
- 1994-02-21 AU AU55294/94A patent/AU669412B2/en not_active Ceased
-
1998
- 1998-06-26 HK HK98106950A patent/HK1007734A1/en not_active IP Right Cessation
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8236720B2 (en) | 2007-07-14 | 2012-08-07 | Refractory Intellectual Property Gmbh & Co. Kg | Unshaped refractory material, a process for producing an earth-moist, unshaped refractory material, and use of the unshaped refractory material |
| CN115229139A (en) * | 2022-06-15 | 2022-10-25 | 攀钢集团攀枝花钢铁研究院有限公司 | Heavy rail steel continuous casting tundish covering agent and adding method thereof |
| CN115229139B (en) * | 2022-06-15 | 2024-02-02 | 攀钢集团攀枝花钢铁研究院有限公司 | Heavy rail steel continuous casting tundish covering agent and adding method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| DE69114412D1 (en) | 1995-12-14 |
| AU5529494A (en) | 1994-05-26 |
| ES2082929T3 (en) | 1996-04-01 |
| KR940001661B1 (en) | 1994-02-28 |
| BR9103497A (en) | 1992-05-12 |
| AU669412B2 (en) | 1996-06-06 |
| EP0472350A1 (en) | 1992-02-26 |
| AU8250791A (en) | 1992-02-20 |
| KR920004315A (en) | 1992-03-27 |
| ZA916453B (en) | 1993-03-31 |
| EP0472350B1 (en) | 1995-11-08 |
| HK1007734A1 (en) | 1999-04-23 |
| DE69114412T2 (en) | 1997-02-27 |
| JPH0497958A (en) | 1992-03-30 |
| JPH0822781B2 (en) | 1996-03-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |